I remember Laravel with Socialite [0]. Laravel is what I usually reach for Web SaaS MVP. You only need a VPS and a managed database for testing out the market and can scale a lot without increasing expenses that much..

[0]: https://laravel.com/docs/13.x/socialite

Take this post down immediately ! /jk

Lol, I developed for entrepreneurs who mostly wanted a working proof of concept of their ideas. I guess now you can vibecode them with SaaS for core technical needs.